Process of producing a nonstretch or low-stretch composite yarn of super high bulkiness

ABSTRACT

Process of producing a nonstretch or low-stretch composite yarn of super high bulkiness. At least one core yarn is fed, and at least one covering yarn having a plurality of filaments is tensioned and relaxed and is then fed in an overfed state to a wrapping point where it is wrapped around the core yarn. The rate of delivery of the covering yarn to the wrapping point is such that the ratio of the length of the covering yarn is from 110-300 percent of the length of the core yarn per unit length of the composite yarn. The composite yarn has a final twist imparted thereto.

United States Patent Inventors Osarnu Wada lbaragi-shi;

Yoshiyuki Sasaki. lbaragi-shi; Masaaki Tomiji, Kashiwara-shi. all of.Japan 838,203

July 1, 1969 Division of Ser. No. 710,138, Mar. 4, 1968. Pat. No.3,495,393 Aug. 3, 1971 Teijin Limited Osaka, Japan Mar. 8, 1967. Mar. 8,1967, Mar. 8, 1967, May 23, 1967, May 23, 1967, May 23, 1967 Japan42/14641, 42/ 14643, 42/14644, 42/43351. 42/43352 and 42/43353 Appl. No.Filed Patented Assignee Priority PROCESSOF PRODUCING A NONSTRETCH ORLOW-STRETCH COMPOSITE YARN 0F SUPER HIGH BULKINESS 5 Claims, 12 DrawingFigs.

US. Cl 57/ 160, 57/12 111:. ct 1165b 81/06 [50] Field oISearch 57/12,140

[56] References Cited UNITED STATES PATENTS 3,068,636 12/1962Masurel.... 57/14 4 X 3,097,471 7/1963 Foster 57/169 X 3,257,793 6/1966Abbott 57/163 3,264,816 8/1966 Jn i 57/ 169 3,410,077 11/1968Marzocchiet al., 57/160X 3,410,078 1 1/1968 Freedman et a1. 57/160 X3,447,302 6/1969 Field, Jr 57/160 X Primary Examiner-Stanley N. GilreathAssislan! E.\-aminer -Werner H. Schroeder Anomey-Wenderoth. Lind &Ponack ABSTRACT: Process of producing a nonstretch or low-stretchcomposite yarn of super high bulkiness. At least one core yarn is fedand at least one covering yarn having a plurality of filaments istensioned and relaxed and is "then fed in an overfed state to a wrappingpoint where it is wrapped around the core yarn. The rate of delivery ofthe covering yarn to the wrapping point is such that the ratio of thelength of the covering yarn is from 1 lO-300 percent of the length ofthe core yarn perunit length of the composite yarn. The composite yarnhas a final twist imparted thereto.

PATENTEUAUG 3m 3,596,459

sum 1 or 5 INVENTORS',

OSMVHJ WIALA,

YOSHIYUKI ISASAKI M10 MASAAKI TDMIII BY Zak ATTORNEKS PATENTED NIB 319?! SHEET 2 BF 5 INVENTORS.

OSAMU wAbA YOSHIYUKL sAsAm am MASAAKI "Town BYLOIMAAMIXMZIN.

ATTORNEYS PATENTEUAUB am 3,596,459

SHEEI'J 0F 5 a mum IW/IIII INVENTORS.

OSAMU WADA- YOSHIYLIKI sAsAW's MASAAKI TOW]! BYQMM. 1MLMM.

ATTORNEY!) FIG. 8

INVENTORS OSAMU WADA YOSHIIYUKI SASAK! MASAAKI TOMIJI ATTORNEYS PATENTEDAUG 3:911 3,596,459

SHEET 5 OF 5 INVENTORS OSA WADA YOS UKI SASAKI MASAAKI TOMIJI ATTORNEYSrefers to any mono- BACKGROUND OF THE INVENTION This invention relatesto a nonyarn of super high bulkiness, and a process of producing saidcomposite yarn. As used herein'the term-"inelastic yarn" ormulti-filament yarn, crimped or uncrimped, of fiber except polyurethaneand rubber, and spun yarn of the same Fiber. For example such ,fibersinclude polyester fiber, polyamide fiber, polyacrylonitrile fiber,polyvinyl chloride fiber, polypropylene fiber, glass fiber, steel fiber;The term crimped yarn" refers to any synthctic'fil'ament yarn crimpedbypresently known processes such as twisting and setting techniques falsetwisting, stuffer box, or any other means of producing texturing.

The well-known c'rimped yarn has a soft feeling because of which it canbe advantageously andbeneficially used in some commercial fields. But ithas the drawback that it has insufficient liveliness when his fabricatedinto apparel, and this problem precludes wider application in commercialfields. A solution has been continuously demanded for this problem. Anysuitableli'veliness of crimped yarn can be attained as desired byincreasing its denier in successive steps for increasing the degree offineness. However,.as the liveliness increases, thesbft feelinginherently possessed by the crimpe'd or low-stretch composite yarndisadvantageously decreases. Furthermore, the Crimped yarn has a defectthat the crimp does not keep the fabric in a bulky statedue to excesstension throughout many steps of the manufacturing process forfabricating it into apparel.

The present invention is directed to a composite yarn in which amajority of the livelinessis imparted by the core and the soft feelingmainly by the covering yarn, so that the resulting yarn will have bothliveliness and a soft feeling.

SUMMARY OF THE INVENTION lt isthe most important object of thepresent'invention to provide a process of producing a nonstretch-orlow-stretch composite yarn having both super high bulkiness and suitablelivelinessi The present invention is characterized by the fact that thecover filaments which-aretin a series'of helical turns are relaxedconsecutively as they are wrapped around the core and both the core andcover are gathered and finally twisted so that the cover is wrappedaround the core to form a non stretch or low-stretch composite yarn ofsuper high bulk. The cover is overfed relative to the core during thewrapping operation so that significant bulkiness can be obtained. Byoverfed is meant that a length of covering yarn greater than the lengthof the core yarn is fed and wrapped around the core yarn.

Further objects and features of the invention will be apparent from thefollowing description taken with the accompanying drawings, in which:

FIGS. 1A and 1B are two schematicviews taken on the opposite side ofacore yarn from each other, greatly enlarged, and showing the yarnaccordingtothe invention; and

FIGS. 2 to 9 are schematic 1 views illustrating various modifiedapparatuses for practicing the process of the invention.

Throughout the Figures, similar'numerals refer to similar parts-of theapparatuses.

Referring now in detail to the drawing, a composite yarn is shown inFIGS. 1A and 1B which yarn includes a core 1 around which a coveringyarn is wrapped. Each filament of the covering yarn is in a series of helical turns and in a bulky condition so that an'unusual bulkiness fiberavailable in staple or filament form can be used as a core isachieved.Any textile,

yarn regardless of whether it is crimped or not. Such fibers includenatural 'fibers such as cotton and wool, and synthetic fibers such aspolyester fiber, nylon fiber, polyvinyl chloride fiber, and such mineralfiber as glass fiber and steel fiber. As for the covering yarn, anyfilament available in crimped form can be included and any operation bywhich the crimp is originally formed can be used such as texturing, useof a stuffer box, gear crimping, torque crimping, edgecrimping, or anyother crimping process. The use of a core with filaments v having adenier not less than twice that of the cover filament has been foundbeneficial in achieving a yarn with the desired properties. lt has beenfound beneficial to limit the denier of the core filament to from 4 to20.

Any synthetic yarn available in crimped form can be used as the coverfilament, and it has been found desirable to limit the denier to lessthan 5.

The foregoing limitations on the fineness of the core and cover filamentare most critical for giving to the resulting yarn the intendedliveliness, due mainly to the core, and the soft feeling due mainly tothe cover. When the critical factors of fineness of bothcore and coverare kept within these limits, the composite yarn resulting from theprocess of this invention has both high bulkiness and liveline-ss,provided that the final twist and the rate. of the cover overfeed aresuitably and reasonably regulated as the case requires. For example, ithas been found that when each filament of the core yarn has a denierless than 4 or more than 20, the desired liveliness can not :beachieved. lt has also been found that when the filament of length of thecover falls below the cover has a denier more than 5, the desired softfeeling cannot be achieved. The cover filaments are longer by about 10to 200 percent, preferably from l0 to 50 percent, than that of the coreper unit length of the resulting composite yarn so that the cover iscaused to cover the core. If the excess of the 10 percent of the corelength per unit length of the resulting yarn, the coverin glthroughoutthe full length of the core has been found to be insufficient. If itrises above 200 percent, the sheath formed by the covering yarn will beloose and the appearance of the yarnwill deteriorate to such a degreethat it cannot be used commercially. The excess of the cover lengthshould be kept in the rangeof from ID to 50 percent relative to thelength of the core. Crimped yarns made by twisting and settingtechniques can be advantageously used as a core to prevent the coverfrom sliding thereon, and such a core will produce added bulkiness. Theuse of two to three filaments with each filament having a denier from l0to 20, has been found to be best for achieving liveliness, and the useof core having total denier of from 50 to l0() and a cover having atotal denier of from 75 to is best for achieving bulkiness.

It is to be noted that the length ofthe core and cover is measured underreasonable tension within the tolerance recognized in the trade.

Referring now to FIG. 2, there is :shown an apparatus for producing acomposite yarn in accordance with this invention by a twisting method. Acore yarn l advances through a pair of nip rolls 3 from any package (notillustrated) and the covering yarn 2 also advances from any package (notillustrated), through a back pair of drafting rolls 4, and theiicethrough an intermediate pair of rolls 5 to the front pair of rolls 6.The linearspeed of the intermediate pair of rolls 5 is greater than thatof theback pair of rolls 4 so that the covering yarn is tensioned whenpassing through the zone defined between the back pair andthe'intermediate pair of rolls. The tension load is withinthe range offrom 0.5 to 2.5 gram per denier and the elongation is generally withinthe range of from 1.5 to 12 percent;relative to the original length.The-covering yarn 2 advances at an angle to the core axis at a fasterspeed than that of the core yarn to facilitate wrapping thecover'therearound. The core-and cover pass together through a snail wire7, a ring traveler Q'and then are wrapped around the bobbin l0 to form apackage 11 thereon. The core and cover are finally twisted together andcover 2 is twisted there-around by rotating the bobbin through a drivenpulley mounted on the spindle (not ilmove up and down in relation to thebobbin 10 to build up a package ll'thereon. A.twist of from 50 to 1,500turns per meter is given to the composite yarn. It has been found thatif the number of turns falls below 50 per meter, the cover slides on thecore and above l,500 the softfeeling decreases. The

' rotational speed of the front pair of rolls 6 is less than that of,the intermediate pair 'of rolls so that the cover passed from theintermediatepair of rolls is immediately relaxed and is inan overfed ordistended state. This makes the cover yarn bulge outwardly with-eachfilament in a distended state so that the bulkiness achieved issignificantly higher than that which could be expected from simply theinherent bulkiness. It should be noted that this phenomenon isingeniously applied to the present invention to obtain unusually higherbulkiness.

The linear speed of the front pair of rollers 6 is significantlylessthan that of-the intermediate pair of rolls 5, so that each of thecovering filaments is urged outwardly so the yarn has a significantlyhigher bulkiness. By slackening-immediately after the tensioning, eachfilame nt'of the covering yarn is caused to separate laterally from theother filaments to achieve a higher bulkiness than that which isinherent in the covering yarn. 3 It should be understood that theunusually higher bulkiness of the cover yarn is achieved by enhancementof the inherent bulkiness. While pairs of rollers have been illustratedand described as a device for producing high bulkiness, it will beunderstood that any tension device can be used in place of rollerdevices, and the distance between the'front pair of rolls 6 and thewrapping point can be changed as conditions may require. For example,the front pair. of rolls .6 can be positioned immediately adjacent thewrapping point. it has been found that the front pair of rolls can beomitted pose of simplifying the apparatus. A

In FIG. '3 is shown another type of apparatus for practicing thisinvention, in which the front pair of rolls 6 additionally. operates asa core feeding pair of rolls, and accurate wrapping of two yarns can beachieved. It is further found that the core can be positioned accuratelynear the axis of the cover at the nip of the front pair of-rolls duringthe wrapping process. This prevents the core yarn from being displacedfrom the center of the resulting.yarn toward the outside of the yarn.

' It should 'be noted that the process does not necessarily requiretwisting immediately after the performance of the l r'elaxing andwrapping procedures. v The apparatus shown in FIGS. 4A--4C carries outtwisting separately after the core has' been wrapped with the cover. It

has been'found beneficial to carry out the process in this mannerto'prevent the crimped cover yarn from being tensioned when the cover isunwound from package 110 for final twisting; since a majority of theunwinding load is borne by the core yarn 1. It has also been found thatwhen the yarn 111 is unwound from the'package on bobbin 110, it isbeneficial to brake the yarn at the letoff position for preventing thecore and cover from being separated from each other during theunwinding. The apparatus inFlG. 4B differs from the apparatus ofFIG..,4A in the manner inwhich the front pair of feed rollers is usedfor feeding not only-the cover but the core in order to achieve accuratemaintenance of the core on the center axis of the cover during thewrapping process.

Now referring to FIG. 5, there is shown modified apparatus for producingthe yarn of this invention. In this apparatus two core yarns areseparately fed and the covering yarnenters the wrapping and twistingpoint so that the rate of over feed of the cover can be advantageouslyincreased, even though a smooth monofilament yarn is used as the coreyarns. For example, when the twomonofilament yarns of polyethyleneterephthalate are used as said two core yarnsand crimped filaments ofthe same material are used as the cover, a rate of overfeed of greaterthan 10 percent can easily beobtained, while the 10 percent rate isfound to be the absolute upper limit when the two monofilaments'aredoubled and twisted and then fed to the wrapping point.

for the pur- Further for this'purpose, the covering yarn need not bewrapped only at the doubling point of the core yarns, but can be wrappedat any point on one of the core'yarns from the feed roll to the doublingpoint.

As shown in F IG. 8, core yarns are fed from packages land 1' by feedrolls 2 and 2'. Covering yarn is .fed from package 5 through feed rolls6 and 6' and is wrapped on one core yarn at point A" between core feedroll 2' and twisting point A. The finished yarn is run through the snailwire 4 and ring traveler on rig 3 onto the yarn package; The .coverihgyarn is preferably wrapped around the core yarn by the'action of thetorque of the core yarn transmitted from the twisting pointiA.

Referring now to FIG. 6, there is shown anothermodified apparatus forcarrying out the process of this invention; In the apparatus, the bottomroller 3' of the feed rolls has the lower portion passing through anadhesive agent in a tank 3", so that Referring now to H0. 7, there isshown a further modified I apparatus for carrying out the process ofthis invention. In the apparatus, a pair of fluted rolls 3 are used asfeed rolls so that the core is crimped and slippage of the cover can beprevented during the twisting operation. I

HO. 9 shows 'another'embodiment similar to that of FIGS. 5 and 8,in-which in addition to the two core yarn packages there are twocovering yarn packages 5 and -5'. Single feed rolls 2 and 6 are providedfor both core yarns and both covering yarns. The respective core yarnsand covering yarns'are joined at points B and C and thetwo covered yarnsdoubled between points B and C and the snail wire 4.

One of the most preferred embodiments of this invention is a process forpreparing a low-stretch high-bulk yarn, characterized in that there isused as the cover a crimped bulky multifilament yarn in which theindividual filaments are distended and which is obtained by twisting inthe S direction (or Z direction.) heat-setting and untwisting, and asthe core there is used a crimped multifilament yarn, and themonofilaments of which have a denier twice or more as large as the coveryarn and obtained by twisting in the opposite direction from the coveryarn, namely, 2 (or S) direction," heat-setting and untwisting. Thelength of the coveryarn is 10-200 percent larger than the core yarn andthe thus produced yarn has imparted thereto a twist of 50-l,500 turnsper meter in the same direction as that in which the core yarn istwisted, namely the Z (or S) direction. A composite yarn obtainedaccording to this process is bulky and has good liveliness because a'crimped yarn having thick monofilaments is used as a core. lt

-' also possesses a soft. feel because of the use of a torquecharacterized in that as the'co ver'there is used acrimped.

crimped yarn having thin monofilaments as a covering yarn. When thecore'iswrapped with the covering yarn and't'wisted, the covering yarnis. twisted in the direction opposite to that employedwhen originallypreparing the covering yarn and consequently the resulting yarn is morebulky.The core yarn is given a substantially larger torque than fthe'covering yarn when it is twisted together with the covering yarn, and istwisted in the direction of twisting the core yarn,.namely in thedirection of less overall yarn torque. Thus, a yarn having an overalllow torque is obtained;

1 Another of the most preferred embodiments of this invention is aprocess for preparing a low-stretch high-bulk yarn,

bulky multifilament yarn in which the individual filaments are dispersedand which is obtained by twisting, in the-S direction- '(or 2direction), heat-setting and untwisti ng, and as the core there is useda crimped multifilament yarn havinga monofila- -ment denier twice ormore as large as that of the cover yarn and haying a number ofmonofilaments less than one-half the number of the first-mentioned yarn.The core yarn is twisted in the opposite direction. namely. the Z (orS)direction, heatset and untwisted. The length of the cover yarn islO--200 percent greater than the core yarn. The cover yarn is posigivenin the 2 direction. Thus, a low-stretch high-bulk yarn was obtainedwhich had a very low torque, balance being maintained by the sum ofZtorque of the core yarn, S torque of the covering yarn and S torquegenerated at the time of tioned surrounding the core yarn with the coreyarn at the 5 twisting. center, and they have imparted to them twist offrom 5()-- Example 3 L500 turns per meter in the opposite direction tothe twisting A 40-denier/two-filament polyester yarn was used as the ofthe core yam. namely the S (or 2) direction. When the core core yarns.Using the apparatus in FIG. 5, a 75-denier/36-filayarn iswrapped withcovering yarn and twisted according to ment false-twisted polyamidecovering yarn having'a trianguthis process, the twist is imparted in thedirection opposite to lar cross section was overfed by 30 percentrelative to the core the twist of the core yarn for the purpose ofuntwisting the yarn, and a twist of 200 turns per meter was given. Thus,a core. yarn. Then the core yarn becomes very bulky. and it isnonstretch high-bulk yarn was obtained. Prior to covering, the possibleto obtain a bulky composite yarn. covering yarn had been elongated by 10percent, and relaxed Exam I 1 so that it was under no tension. Thecovering yarn was fed into i a point where the two core yarnsintersected each other. They A 45-denier/three-filament false twistedpolyester yarn (Z were twisted together while part of the covering yarnwas torq e) w used as core yarn-and covered with a nibeing held betweenthe two core yarns, and were associated er/48-filament false-twistedpolyester yam (Z torqu With tightly into a covered yarn. Theobtainedyarn had good bulkilhe pp r 0f lG.i3, prior towrapping the coreyarn, th ness, and had a soft feeling and unique luster. lt was suitableas covering yarn had been widened to a widthof about7 mm. in a materialfor woven fabrics. a direction at right angles to the yarn axis byelongating it by 5 Example 4 percent and. relaxing it so that it wasunder no tension. The Using the apparatus in FIG. 4, a low-stretchhigh-bulk yarn covering yarn was overfed by 30 percent relative to thecore was prepared in the same manner as in example 1 using a 75- yarn,and the core yarn was fed into the center portion of thedenier/IS-filament false-twisted yarn as a core and a IOO-denicoveringyarn. A low-stretch super highbulk yarn was ob er/36-filamentside-by-side type conjugate filament yarn comtained by imparting tothecomposite yarn a final twist of 600 posed ofa polyethylene terephthalateresin and'a polyethylene turns per meter in the Z direction. Two suchlow-stretch super naphthalate resin as a cover. high bulky yarns weredoubled, and given a final twist of 480 Example 5 turns per meter in theS direction to make a material for A spun yarn of 64 S (metric count)from out staples of woven fabric. polyethylene terephthalate (4d, 76:mm.) was used as a core, A woven fabric of a matt weave was preparedfrom the said and a false-twisted l50-denier/48-filament polyethyleneyarn, and subjected to an ordinary finishing process such asterephthalate was used asa covering yarn. Using the apparatus scouring,relaxing, heat-setting, dyeing and again heat-setting. in H0. 6, powderof polyethylene terephthalate with which It had the properties as shownin the following table. For the 35 mole percent of isophthalic acid hadbeen copolymerized was sake of comparison, awoven fabric was preparedfrom ordinaadded to the surface of the core yarn, and the thus treatedry false-twisted yarns using the same technique both in weavcore yarnwas wrapped with a covering yarn which had been ing and in finishing.The said ordinary false-twisted yarn was overfed by 70 percent relativeto the core. A nonstretch highprepared by imparting a twist of 200 turnsper meter in the Z bulk yarn was obtained by covering in the same manneras in direction to a l-denier/48-filament (Z torque) polyester 40example I. The twist imparted at this time was 300 turns per yarn, andimparting a final twist of I turns per meter in the 5 meter. Theobtained yarn was dry heat-treated at 200 C., and direction to two ofsuch polyester yarns which had been dollcoalesced points were developedpartly on the core and coverbleding yarns.

RESULT OF TESTING OF WOVEN FABRICS Woven fabric Woven fabric preparedfrom prepared from the yarns of the the ordinary presentinvenfalse-twisted Direction 7 Unit tion yarns Density ii 3r?.1Etiiiifiii; 1;: 3% Thickness... \Irn. 0.51 0.46 Bnlkiness Cm. /g 2.6Bending stiffness. Warp, G.-cm. ,'cm 29.0X10 21.8X 0- Bendingrecovery... Welt Percent 90.0 83.2

The bending stiffness and bending recovery were measured in accordancewith. the description in the Journal of the Textile institute, 1964,vol. 55, T 516.

As can be seen from the above results, the fabric woven from the yarnsof the present invention has very good bulkiness, and an excellentliveliness. It is impossible to give a definite measured value to theliveliness since the liveliness can only be sensed by humans. it isgenerally said, however, that the liveliness is excellent when thebending stiffness is appropriate and the bending recovery is good.Incidentally, the fabric woven from the yarn according to the presentinvention was far softer and had an excellent hand as compared with thewoven fabric prepared from the ordinary false-twisted yarns.

Example 2 A Z torque 75-denier/eight-filament false-twisted polyesteryarn was used as a core. Using the apparatus in FIG. 2, and S torquel00-denier/48-filament false-twisted polyester yarn was overfed by 20percent relative to the core yarn in-the same While several embodimentsof this invention have been illustrated and described herein, it will beapparent that modification thereof may be made without departing fromthe scope ofthe invention as defined in the appended claims.

What we claim is:

1. A process of producing a nonstretch or low-stretch composite yarn ofsuper high bulkiness, comprising the steps of a feeding at least onecore yarn, tensioning a crimped covering yarn having a plurality offilaments at a tension load of from 0.5 to 2.5 grams per denier toremove the crimps therefrom, and then relaxing said covering yarn,feeding the relaxed covering yarn with an overfeed to a wrapping point,wrapping said relaxed covering yarn around the core as a cover to form acomposite yarn, and imparting twist to the composite yarn, the rate ofdelivery of the covering yarn to the wrapping point being such that theratio of the length of the covering yarn is from 1 10 to 300 percent ofthe length of the core yarn per unit manner as example I, and a twist of300 turns per meter was length of the composite yarn.

2 The process as claimed in claim I wherein the tensioned and relaxedcovering yarn is fed into a pair of feed rollers and the separately fedcoreyarn is joined to the covering yarn at the feed rollers and isthereby covered with the covering yarn. 3. A process of producing anonstretch or low-stretch composite yarn of super high bulkiness,comprising the steps of forming at least two separate yarns into a coreyarn by separately and angularly feeding the separate yarns to a pointand twisting them at said point; feeding said one core yarn; tensioninga erimped covering yarn having a plurality of filaments to remove thecrimps therefrom and then relaxing said covering yarn; feeding therelaxed covering yarn in an overfed state to said twisting point andwrapping said relaxed coveringyarn around the core as a cover to form acomposite yarn, the rate of delivery of the covering yarn to thetwisting point being such that the ratio of the length of the coveringyarnis from yarn, feeding the relaxed covering yarn in an overfed stateto a wrapping point and wrapping said relaxed covering yarn around thecore as a cover to form a composite yarn. the rate of delivery of thecovering yarn to the wrapping point being such that the ratio of thelength of the covering yarn is from 110-300 percent of the length of thecore yarn per unit length of the composite yarn, and finally impartingalwist to the composite yarn.

5. A process of producing a nonstretch or low-stretch composite yarn ofsuper high bulkiness. comprising the steps of forming at least twoseparate yarns into, a core yarn by separately and angularly feeding theseparate yarnsto a point and twisting them at said point; feeding saidcore yarn; tensioning a erimped covering yarn having a plurality offilaments to remove the crimp therefrom and then relaxing said coveringya'rn; feeding the relaxed covering yarn in an overfed state to a pointwhich lies ahead of said twisting point with respect to the feeddirection and wrapping the relaxed covering yarn around the core as acover to form a composite yarn. the rate of delivery of the coveringyarn to the wrapping point being such that the ratio of the length ofthe covering yarn is from -300 percent of the length of the core yarnper unit length of the composite yarn; and finally imparting a twist tog the composite yarn.

2. The process as claimed in claim 1 wherein the tensioned and relaxedcovering yarn is fed into a pair of feed rollers and the separately fedcore yarn is joined to the covering yarn at the feed rollers and isthereby covered with the covering yarn.
 3. A process of producing anonstretch or low-stretch composite yarn of super high bulkiness,comprising the steps of forming at least two separate yarns into a coreyarn by separately and angularly feeding the separate yarns to a pointand twisting them at said point; feeding said one core yarn; tensioninga crimped covering yarn having a plurality of filaments to remove thecrimps therefrom and then relaxing said covering yarn; feeding therelaxed covering yarn in an overfed state to said twisting point andwrapping said relaxed covering yarn around the core as a cover to form acomposite yarn, the rate of delivery of the covering yarn to thetwisting point being such that the ratio of the length of the coveringyarn is from 110-300 percent of the length of the core yarn per unitlength of the composite yarn; and finally imparting a twist to thecomposite yarn.
 4. A process of producing a nonstretch or low-stretchcomposite yarn of super high bulkiness, comprising the steps of feedingat least one core yarn by passing it through a pair of fluted nip rollsfor crimping the core yarn, tensioning a crimped covering yarn having aplurality of filaments to remove the crimp therefrom and then relaxingsaid covering yarn, feeding the relaxed covering yarn in an overfedstate to a wrapping point and wrapping said relaxed covering yarn aroundthe core as a cover to form a composite yarn, the rate of delivery ofthe covering yarn to the wrapping point being such that the ratio of thelength of the covering yarn is from 110-300 percent of the length of thecore yarn per unit length of the composite yarn, and finally imparting atwist to the composite yarn.
 5. A process of producing a nonstretch orlow-stretch composite yarn of super high bulkiness, comprising the stepsof forming at least two separate yarns into a core yarn by separatelyand angularly feeding the separate yarns to a point and twisting them atsaid poinT; feeding said core yarn; tensioning a crimped covering yarnhaving a plurality of filaments to remove the crimp therefrom and thenrelaxing said covering yarn; feeding the relaxed covering yarn in anoverfed state to a point which lies ahead of said twisting point withrespect to the feed direction and wrapping the relaxed covering yarnaround the core as a cover to form a composite yarn, the rate ofdelivery of the covering yarn to the wrapping point being such that theratio of the length of the covering yarn is from 100-300 percent of thelength of the core yarn per unit length of the composite yarn; andfinally imparting a twist to the composite yarn.